Inkjet printers eject drops of liquid ink from inkjet ejectors to form an image on an image receiving surface, such as an intermediate transfer surface, or a media substrate, such as paper. Full color inkjet printers use a plurality of ink reservoirs to store a number of differently colored inks for printing. A commonly known full color printer has four ink reservoirs. Each reservoir stores a different color ink, namely, cyan, magenta, yellow, and black (CMYK) ink, for the generation of full color images.
Phase change inkjet printers utilize ink that remains in a solid phase at room temperature, often with a waxy consistency. After the ink is loaded into a printer, the solid ink is transported to a melting device, which melts the solid ink to produce liquid ink. The liquid ink is stored in a reservoir that may be either internal or external to a printhead. Multi-color printers may include multiple printheads with each printhead being fluidly connected to an ink reservoir to enable each printhead to receive and eject ink a single color of ink. An example of a common multi-color printer has a plurality of printheads that eject inks having the CMYK ink colors. Other multi-color systems may include one or more printheads that eject ink drops of multiple different colors from a single printhead. Printheads that eject more than one color of ink are supplied from multiple sources of ink. Additionally, these systems may also include at least one printhead configured to eject ink drops having a single color. In either type of printer, the liquid ink is provided to the inkjet ejectors of the printheads as needed.
In printers having a “sleep” mode, the amount of heat applied to ink reservoirs during periods of inactivity is lower than during imaging operations to reduce the consumption of electrical power in the printer. During sleep mode, melted ink may solidify. Upon receiving a request to print an image, all heating devices that apply heat to produce liquid ink in the reservoirs and printheads are activated to enable inkjet printing of liquid ink. Consequently, receipt of a request to print an image immediately increases the energy consumption of the printer from the energy consumption level occurring during the sleep mode. Reductions in the energy consumption of a printer are desirable.